Abstract
In this work, the gelation kinetics and fractal character of lysozyme gel matrices developed in tetramethylurea (TMU)-water media were investigated. Gelation times were determined from the temporal crossover point between the storage, G′, and loss, G″, moduli, as a function of the binary solvent composition and of protein concentration. The inverse dependence of the upper limit of the linear viscoelastic region (γ0) on protein concentration indicate that the lysozyme gels belong to the "strong link" kind, a gel category where interparticle links are stronger than intraparticle ones. Lysozyme gel fractal dimensions (Df) were determined from the analysis of rheological data according to a scaling theory by Shih et al. [Phys. Rev. A 42 (1990) 4772-4779] and were found to be compatible with a diffusion-limited cluster-aggregation kinetics (DLCA) for lysozyme gels formed at the TMU mass fraction in the binary organic-aqueous solvent, wTMU = 0.9, and with a reaction-limited cluster aggregation kinetics (RLCA) for wTMU in the 0.6 ≤ wTMU ≤ 0.8 range.
| Original language | English |
|---|---|
| Pages (from-to) | 394-401 |
| Number of pages | 8 |
| Journal | Journal of Colloid and Interface Science |
| Volume | 289 |
| Issue number | 2 |
| Early online date | 1 Jun 2005 |
| DOIs | |
| Publication status | Published - 15 Sept 2005 |
Funding
E.P.G. Arêas is grateful to FAPESP (Brazil) for the financial support of this work. M.A. da Silva acknowledges a doctorate scholarship from CNPq (Brazil). Authors thank André P.G. Arêas for his support with the statistical analysis of data.
Keywords
- Fractals
- Gels
- Lysozyme
- Protein
- Rheology
- Tetramethylurea
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry